1. Field of the Description
The present description relates, in general, to wheeled vehicles and wheel design, and, more particularly, to vehicle wheels that are non-circular that include, one or more devices to compensate for variances in the wheel radius to provide a smooth or planar/consistent ride for the vehicle frame supported on the non-circular wheel(s).
2. Relevant Background
In the entertainment industry, there is an ongoing search for eye-catching and surprising visual effects. For example, theme parks and other entertainment venues often use vehicles in shows and parades to entertain their visitors or an audience, and it is desirable to design the parade vehicles, bicycles, vendor carts, fide vehicles, wheeled-based robotic platforms/floats, and so on so as to provide a visual impact and not just be functional.
Historically and presently, vehicles are supported upon circular wheels and use these wheels for their main mode of locomotion, e.g., the vehicle rolls upon a road or other surface on one to four or more wheels. Circular wheels are desirable for vehicles because they provide a constant radius and a fixed center of rotation that together provides the vehicle (or its frame connected to the center of rotation) a smooth and constant/consistent motion on a flat surface. Despite the many advantages of the basic circular wheel, there is a large potential for entertainment with vehicles having wheels with a variety of shapes including non-circular shapes. The entertainment comes in part due to the fact that a non-circular wheel is unexpected and because humans instinctively associate a rolling motion with a round wheel, which increases the fascination with a non-circular wheel that rolls in a similar way to a round wheel.
Some efforts to use non-circular wheels have been created, but these have typically required a specially-formed rolling surface. For example, there have been a number of vehicle designs that utilize square and other shaped wheels that are used to roll upon a non-flat surface. Specifically, a vehicle with square wheels may be used to roll upon a non-flat/planar road or surface formed with inverted catenaries with arc lengths equal to the side lengths of the square wheel, which maintains a relatively constant height of the center of rotation. These types of vehicles do not require additional mechanisms to maintain a fixed ride height (which provides a smooth ride for the vehicle frame), but they are limited to rolling on a very specifically formed and shaped riding surface.
Another vehicle design has been proposed that uses constant diameter wheels of differing shapes to roll on a flat surface with a relatively smooth ride provided for the supported vehicle frame. For example, a bicycle may be provided that has non-circular wheels of a constant diameter (as measured about the periphery of the entire wheel), and a subset of these shapes is sometimes referred to as Reuleaux shapes or objects. These vehicles exploit the characteristics of a constant diameter wheel or shape to allow them to roll a vehicle on flat surfaces. The bicycle, for example, is adapted to provide a second planar surface on its frame that is parallel to the ground or riding surface plane and that is positioned a distance equal to the fixed diameter of the wheel away from the riding surface. In this manner, the vehicle frame is supported upon the wheel via the second planar surface device(s) and not to the center of rotation as in a common bicycle or other vehicle. While providing a visually surprising effect, these vehicles are limited to use with a wheel with a constant diameter and not useful for more oddly or arbitrarily shaped wheels and are not modular in that they require significant modifications of a vehicle's frame or body.